The invention pertains to a process for creating low cost fiber reinforced aerated concrete and to compositions for such concrete.
The prior art has generally centered on production of either autoclave aerated cellular concrete (AAC) or variations thereof to produce a lightweight concrete with good strengths for use as building blocks or panels. Alternately, prior art has been identified that can produce a fiber reinforced cellular concrete using either Al or foam. AAC processes rely on expensive autoclave equipment to cure a mixture of cement, sand, lime and other materials that have been aerated by the reaction of powdered Al and high pH cement/lime. Various other processes have been proposed with systems based upon the use of aerating and other agents and casting forms to produce the desired shape of material or cutting the uncured material with wires. Most of these processes rely on a high percentage of cement in the mixture to achieve the desired product strength.
The system disclosed herein produces fiber reinforced aerated concrete in a variety of precise shapes through the application of a unique process. The compositions incorporate the use of a high percentage of low cost coal fly ash, cement, selected fiber materials, other reagents, and selected activating reagents to produce fiber reinforced aerated concrete. The process combines and thoroughly mixes these materials with water in a high-speed dispersion mixer. The mixture is then placed in a mold and cured for 12-24 hours at naturally elevated temperatures generated by chemical reactions taking place in the monolithic mass. Following additional curing of 1-2 days, the material is cut into precise block or panel shapes by sawing. The sawn materials are then shipped to the construction site for assembly using standard aerated concrete joining techniques.
The present invention will be explained further in conjunction with the appended drawing and the following detailed description.